Reed W. Spencer

Drilling dynamics measurements at the drill bit to address today's challenges

In todays operations for oil and gas exploration and production the drilling systems are commonly subjected to dynamic dysfunctions that can compromise the quality of the wellbore, increase the time spent on the job, and result in downhole tool failures. Measurement of downhole dynamics is traditionally performed using tools located in the drillstring above the drill bit. Until recently, obtaining accurate measurement of individual vibration components at the bit remained a challenge, especially in applications requiring that bottomhole assembly configuration and hydraulic horsepower at the bit be minimally disturbed. In this paper, laboratory and field measurements gathered with an in-bit measuring device that meets these requirements are presented. The paper demonstrates that accurate measurements of downhole dysfunctions and angular velocity can be obtained at the bit. It also presents field case studies that show how the information extracted can be used to optimize drilling performance.